O_3-BAC组合工艺深度净化MBR出水的中试研究

采用臭氧-生物活性炭（O3-BAC）组合工艺对某工业园区再生水厂MBR出水进行了深度净化的中试研究,主要考察了组合工艺各节点对常规指标的处理效果。结果表明,臭氧投加量约3 mg/L（H2O）、臭氧接触塔接触时间为30min、活性炭滤池空床接触时间（BECT）为15 min时,O3-BAC组合工艺能有效去除水中色度、浊度,平均色度和浊度分别从21度和7.8 NTU降至3度和2.0 NTU以下;组合工艺对UV254、高锰酸盐指数的平均去除率分别约为39%和35%;对NH4＋-N有一定的去除,去除率为58%～77%;组合工艺对粪大肠菌群去除效果显著,平均去除率在95%以上。O3-BAC组合工艺是一种有效工业园区再生水深度净化技术。     

直接过滤-臭氧-生物活性炭工艺用于城市污水二级处理出水深度处理的研究

采用砂滤-臭氧-生物活性炭工艺在北京市某污水处理厂开展了以污水再生回用为目的的城市污水深度处理中试研究.在臭氧消耗量5 mg/L,接触时间20 min,生物活性炭空床停留时间(EBCT)为20 min的条件下,出水浊度为1.5 NTU左右,色度接近0,UV254从0.162 cm-1降低到0.08 cm-1,DOC和CODMn分别从10.1 mg/L和12.8 mg/L降低到6 mg/L左右.由于对生物活性炭柱进行了曝气供氧,NH4 -N从40 mg/L降低到5 mg/L左右.     

直接过滤-臭氧-生物活性炭工艺用于城市污水二级处理出水深度处理的研究

采用砂滤-臭氧-生物活性炭工艺在北京市某污水处理厂开展了以污水再生回用为目的的城市污水深度处理中试研究。在臭氧消耗量5mg／L，接触时间20min，生物活性炭空床停留时间（EBCT）为20min的条件下，出水浊度为1．5NTU左右，色度接近0，UV254从0．162cm^-1降低到0．08cm^-1，DOC和CODMn分别从10．1mg／L和12．8mg／L降低到6mg／L左右。由于对生物活性炭柱进行了曝气供氧，NH4^- N从40mg／L降低到5mg／L左右。     

水解酸化+A/O工艺对石化废水不同分子量有机物去除效果评价

对某典型石化企业综合污水处理厂"水解酸化+A/O"处理工艺各单元出水不同分子量区间的有机物含量及光谱特性进行了表征。研究表明,石化企业综合污水处理厂各处理单元出水DOC以分子量1 kDa的有机物为主;处理工艺对废水COD、DOC和UV254的总去除率分别为84.58%、86.22%和72.92%,分子量1 kDa、3~5 kDa、10~30 kDa、30~100 kDa的DOC去除率达90%左右,分子量5~10 kDa和100 kDa的DOC增加了28.57%和43.90%;分子量1 kDa的UV254的去除率为76.27%;水解酸化池对分子量30~100 kDa的有机物去除率达90.87%,缺氧段对分子量1~3 kDa的DOC去除率达92.86%,缺氧出水分子量3~10 kDa和30~100 kDa的DOC浓度较水解酸化出水有较大增加,好氧段对缺氧段出水中分子量30~100 kDa、5~10 kDa和3~5 kDa的有机物有很好的去除作用,去除率分别为80.85%、43.46%和72.32%,而分子量1~3 kDa的DOC浓度有所增加。各出水在260~270 nm有紫外吸收峰。各分子量区间DOC的SUVA值随处理工艺沿程增大,废水有机物芳香度提高,UV253/UV203呈减小趋势。     

Catalytic activity of Ru/Al2O3 for ozonation of dimethyl phthalate in aqueous solution

With dimethyl phthalate as the model pollutant and Ru/Al(2)O(3) as catalyst, this paper systemically investigates the removal of total organic carbon (TOC) of system. Our results have confirmed that Ru/Al(2)O(3) can significantly increase the effect of ozonation. TOC removal in 120 min can reach 72% while only 24% with ozone alone. The optimal catalyst preparing condition was 0.1 wt% Ru content, 600 degrees C calcination temperature, 0.5-1.0mm particle diameter, which is characterized by a high surface area and a large population of surface active sites. The contrasting experiments of ozone alone, catalyst adsorption after ozonation, and catalytic ozonation confirmed that catalytic reaction was the most important process to TOC removal in system with Ru/Al(2)O(3) as catalyst.     

Improvement of DOC removal by multi-stage AOP-biological treatment

The single and multi-stages advanced oxidation process (AOP)-biological treatments were evaluated to apply for drinking water treatment, especially for the water containing less susceptible dissolved organic carbon (DOC) to ozone, comparing with the ozonation-biological treatment. Minaga reservoir water and the secondary effluent from a Municipal wastewater treatment plant were used as dissolved organic matter (DOM) solutions. DOC removals after 60 min AOP-biological treatment were 62% and 41% in the Minaga reservoir water and the secondary effluent, respectively, whereas those in the ozonation-biological treatment only 40% and 15% of DOC were removed, respectively. The result indicated that the single-stage AOP-biological treatment could improve DOC removal in comparison with the single-stage ozonation-biological treatment. This is because the AOP mineralized both biodegradable dissolved organic carbon (BDOC) produced in the early stage of oxidation and non-biodegradable dissolved organic carbon (NBDOC), whereas only BDOC was mineralized by further ozonation and NBDOC was not oxidized in the ozonation-biological treatment. The multi-stage treatment could not improve DOC removal in comparison with the single-stage treatment in the ozonation-biological treatment for the secondary effluent containing less susceptible DOC to ozone. However, the multi-stage AOP-biological treatment significantly reduced DOC and achieved 71% of DOC removal by 4 times repetition of 15 min oxidation, whereas DOC removal was 41% in the single-stage AOP-biological treatment for the same oxidation time. The improvement of DOC removal by the multi-stage AOP-biological treatment was due to BDOC removal as a radical scavenger by subsequent biological treatment in the early stage of oxidation and direct mineralization in the latter stage of oxidation.     

臭氧-曝气生物滤池深度处理印染制革园区废水

针对浙江省某印染制革园区污水处理厂二级生化出水，开展了处理规模36~120 t/d的臭氧-曝气生物滤池中试研究，对臭氧预处理进行优化，考察了臭氧预处理优化后与不同填料BAF组合对污染物的去除情况。结果表明，当臭氧预处理条件为投加量25 mg/L，三点投加且投加比为6：3：1，臭氧接触时间为42 min时，处理效果较好且最经济；在此臭氧预处理条件下，臭氧-活性炭BAF的出水COD能稳定在50 mg/L，色度稳定在5度，满足《城镇污水厂污染物排放标准》（GB 18918-2002）中的一级B排放要求；臭氧-混合填料BAF的出水COD和色度也能基本达到一级B排放要求；而臭氧-陶粒BAF出水COD和色度都未能达到一级B排放要求。     

臭氧/ 生物活性炭深度处理循环养殖废水

随着工厂化循环水养殖的不断发展,高浓度循环养殖废水对环境污染日益严重.为实现环境友好和资源节约,采用臭氧/生物活性炭对循环养殖废水进行深度处理中试研究.实验结果表明,臭氧化臭氧最佳投加量为4 mg/L,显著增强水体的可生化性,使TOC(总有机碳)/UV254(在波长为254 nm处的单位比色皿光程下的紫外吸光度)提高80%.臭氧/生物活性炭对循环养殖废水中的有机物和氨氮具有良好的去除效果.臭氧/生物活性炭对TOC、高锰酸盐指数和UV254的最终去除率比生物活性炭分别高11.9%、13.4%和6.5%.臭氧/生物活性炭和生物活性炭对氨氮的最终去除率分别为96.0%、90.7%.     

Heterogeneous and homogeneous catalytic ozonation of benzothiazole promoted by activated carbon: kinetic approach

Ozone oxidation combined with activated carbon adsorption (O(3)/AC) has recently started to be developed as a single process for water and wastewater treatment. While a number of aspects of aqueous ozone decomposition are well understood, the importance and relationship between aqueous ozone decomposition and organic contaminant degradation in the presence of activated carbon is still not clear. This study focuses on determining the contribution of homogeneous and heterogeneous reactions to organic contaminants removal in O(3)/AC system. Benzothiazole (BT) was selected as a target organic pollutant due to its environmental concern. A reactor system based on a differential circular flow reactor composed by a 19 cm(3) activated carbon fixed bed column and 1 dm(3) storage tank was used. Ozone was produced from pure and dry oxygen using an Ozocav ozone generator rated at 5 g O(3)h(-1). Experimental results show that BT removal rate was proportional to activated carbon dosage. Activated carbon surface contribution to BT oxidation reactions with ozone, increased with pH in absence of radical scavengers. The radical reaction contribution within the pH range 2-11 accounted for 67-83% for BT removal in O(3)/AC simultaneous treatment. Results suggest that at pH higher than the pH of the point of zero charge of the activated carbon dissociated acid groups such as carboxylic acid anhydrides and carboxylic acids present on activated carbon surface could be responsible for the observed increase in the ozone decomposition reaction rate. A simplified mechanism and a kinetic scheme representing the contribution of homogeneous and heterogeneous reactions on BT ozonation in the presence of activated carbon is proposed.     

气水比对曝气生物活性炭处理原水的影响

针对从臭氧-活性炭工艺中开发出来的预臭氧-曝气生物活性炭,在不同气水比工况下进行实验,分析了不同气水比对曝气生物活性炭处理微污染原水的影响与作用。结果表明:在滤速为8～12 m/h,空床接触时间为11.5～15.4 min,装填密度为510 g/L条件下,不同气水比对去除氨氮的影响大于对CODMn的影响。气水比为0.3∶1时,对氨氮浓度为1.65～2.10 mg/L范围的进水平均去除率为81.9%,亚硝酸盐氮平均积累率为1.4%,CODMn去除率为70.6%。当气水比逐渐增加时,氨氮平均去除率有所提高,亚硝酸盐氮积累率则有所下降,对较低浓度的CODMn影响不大。     

The degradation of dissolved organic nitrogen associated with melanoidin using a UV/H2O2 AOP

The aim of this study was to examine the simultaneous degradation of dissolved organic nitrogen (DON) and associated colour from wastewater containing melanoidins by an advanced oxidation process (AOP). UV irradiation of H2O2 was used as the mechanism to create the hydroxyl radical for oxidation. Melanoidins are large nitrogenous organic compounds that are refractory during biological wastewater treatment processes. The simultaneous degradation of DON and colour, present as a result of these compounds, was investigated using an AOP. The oxidation process was much more capable of removing colour (99% degradation), dissolved organic carbon (DOC) (50% degradation) and DON (25% degradation) at the optimal applied dose of hydrogen peroxide for the system (3300 mg l(-1)). This indicated that colour and DON removal were decoupled problems for the purpose of treating melanoidin by an AOP and thus colour removal can not be used as an indication of DON removal Colour was caused by organic molecules with molecular weight greater than 10 kDa. Oxidation caused a partial reduction of the DON (41-15% of the total dissolved nitrogen) and DOC (29-14% of the DOC) associated with the large molecular weight fraction (>10 kDa) and almost complete colour removal (87-3% of the total colour). The degraded DON was mostly accounted for by the formation of ammonia (31% of the nitrogen removed from the large fraction) and small molecular weight compounds (66% of the nitrogen removed from the large fraction). The degraded DOC appeared to be mostly mineralised (to CO2) with only 20% of the degraded compounds appearing as small molecular weight DOC.     

高效生物活性炭吸附工艺去除水体中甲基叔丁基醚的初步研究

通过对来自美国加州拉玛达(La Mirada)市污染点的原始菌源炭进行甲基叔丁基醚(MTBE)降解菌生物强化,试图建立具有更有效MTBE降解效果的生物活性炭(BAC)功能,尝试利用新形成的菌源炭覆盖新鲜椰壳活性炭(GAC)而达到新BAC功能的快速有效启动,并考察不同空床停留时间(EBCT)、GAC吸附饱和状态对BAC功能启动的影响。同时,对具有成熟BAC功能的炭柱中的混合菌落进行基于16SrDNA的聚合酶链反应(PCR)—变性梯度凝胶电泳(DGGE)分析,以确定混合菌落中的主要功能菌种属。结果表明,针对模拟的低MTBE浓度进水,新鲜GAC和菌源炭A添加体积分数分别为40%和60%的NAS柱出水MTBE质量浓度最终稳定低于0.005mg/L,平均去除率接近99%,出水MTBE完全达到美国环境保护署(EPA)的饮用水建议阈值(<20μg/L),建立了成熟的BAC功能;成熟的菌源炭可在30d左右通过覆盖法迅速实现新BAC功能的启动;EBCT的延长有利于新BAC功能的启动和维持,接种初期应尽量采用较长EBCT以保证取得足够和稳定的生物量;MTBE吸附饱和前后的GAC在启动新BAC功能时存在差异,鉴于吸附饱和GAC在接种初期会因MTBE解吸而造成出水MTBE浓度较高,建议采用新鲜活性炭覆盖需接种炭柱;BAC功能成熟炭柱中包括的5种主要菌种里有4种为未培养微生物,1种为未分类菌种,其理化性质和具体属性尚不明确。     

Effect of preozonation on the characteristic transformation of fulvic acid and its subsequent trichloromethane formation potential: presence or absence of bicarbonate

The effects of bicarbonate on the characteristic transformation of fulvic acid (FA) and its subsequent trichloromethane formation potential (TCMFP) were investigated in the process of preozonation. Dissolved organic carbon (DOC) removal rate and the residual aqueous ozone concentration during preozonation were measured with different bicarbonate concentration. The presence of bicarbonate inhibited DOC removal and decreased TCMFP yields in the initial oxidation period. In order to explain these phenomena, the molecular weight (MW) distribution (<5, 5-10, 10-30, and >30 kDa) and corresponding TCMFP were investigated for FA and its subsequent oxidation products. Furthermore, transformation of molecular structure, based on MW distribution, was also characterized with Fourier transform infrared (FTIR) spectrum. Bicarbonate showed different inhibiting effects on TCMFP of organic species with different MW, and more significant TCMFP decrement was observed for the high MW fraction (>30 kDa) than for the low MW fractions. Preozonation led to obvious reduction on DOC and UV254 in most of MW fractions wherever bicarbonate was present or not, demonstrating that ozone contributed to both organics mineralization and structure variation, synchronously. As being indicated from the results of FTIR and gas chromatography-mass spectrometry, the functional groups such as alcohols, epoxides and phenols, the formation of which was promoted with hydroxyl radicals (.OH) and would be remarkably inhibited by bicarbonate, were responsible for the increment of TCM precursor's concentration during ozonation. Results of these studies confirmed low dosage bicarbonate affecting the ozonation pathways, influencing the intermediate species formation and impacting its subsequent TCMFP yields through inhibiting the .OH radicals reactions mainly occurred in high MW fractions.     

Effect of VOC loading on the ozone removal efficiency of activated carbon filters

Activated carbon (AC) filters are used widely in air cleaning to remove volatile organic compounds (VOCs) and ozone (O(3)). This paper investigates the O(3) removal efficiency of AC filters after previous exposure to VOCs. Filter performance was tested using coconut shell AC and two common indoor VOCs, toluene and d-limonene, representing low and high reactivities with O(3). AC dosed with low, medium and high loadings (28-100% of capacity) of VOCs were exposed to humidified and ozonated air. O(3) breakthrough curves were measured, from which O(3) removal capacity and parameters of the Elovich chemisorption equation were determined. VOC-loaded filters were less efficient at removing O(3) and had different breakthrough behavior than unloaded filters. After 80 h of exposure, VOC-loaded AC samples exhibited 75-95% of the O(3) removal capacity of unloaded samples. O(3) breakthrough and removal capacity were not strongly influenced by the VOC-loading rate. Toluene-loaded filters showed rapid O(3) breakthrough due to poisoning of the AC, while pseudo-poisoning (initially higher O(3) adsorption rates that rapidly decrease) is suggested for limonene-loaded filters. Overall, VOC loadings provide an overall reduction in chemisorption rates, a modest reduction in O(3) removal capacity, and sometimes dramatic changes in breakthrough behavior, important considerations in filter applications in environments where both O(3) and VOCs are present.     

中置生物活性炭滤池的选炭

实验通过对传统臭氧-生物活性炭工艺的调整,采用臭氧-曝气生物活性炭滤池-砂滤池工艺,对比研究了4mm柱状炭、4 mm破碎炭和1.5 mm柱状炭3种不同类型活性炭用于给水深度处理的运行效果。结果表明,粒径为1.5 mm的柱状炭对有机物和氨氮的去除效果以及出水浊度方面优于其他2种活性炭,但炭滤池水头损失偏大,且不够稳定,适当增加柱状炭的粒径可稳定和降低滤池的水头损失。     

Comparison of dissolved-organic-carbon residuals from air- and pure-oxygen-activated-sludge sequencing-batch reactors.

Literature shows that full-scale pure-oxygen activated sludge (O2-AS) wastewater treatment plants (WWTPs) generate effluents with higher dissolved-organic carbon (DOC) concentrations and larger high-molecular-weight fractions compared to air-activated-sludge (Air-AS) WWTP effluents. The purpose of this paper was to evaluate how gas supplied (air vs. pure oxygen) to sequencing-batch reactors affected DOC transformations. The main conclusions of this paper are (a) O2-AS effluent DOC is more refractory than air-AS effluent DOC; and (b) O2-AS systems may have higher five-day biochemical oxygen demand removals than air-AS systems; however, in terms of COD and DOC removal, air-AS systems are better than O2-AS systems. Analysis of a database from side-by-side O2- and air-AS pilot tests from literature supported these observations.     

Characteristics of biotic and abiotic removals of dissolved organic carbon in wastewater effluents using soil batch reactors.

Biodegradable dissolved organic carbon (BDOC) analyses and abiotic adsorption of dissolved organic carbon (DOC) from different wastewater effluent were conducted to evaluate biotic and abiotic removal mechanisms as a function of the initial DOC concentration and source of DOC using soil batch reactors. To obtain high DOC concentrations, a laboratory-scale reverse osmosis unit was used. It was found that BDOC fraction was independent of the initial DOC concentration and was dependent on the source of wastewater and/or the types of wastewater treatment. The BDOC fractions varied from 9 to 73%. Trickling filter effluent (Tucson, Arizona) showed the highest BDOC, ranging from 65 to 73% biodegradable, while wastewater treated by the soil aquifer treatment (SAT) (NW-4) was found to be most refractory, with DOC removals of 9 to 14%. For nitrified/denitrified tertiary effluent (Mesa, Arizona) and secondary effluent (Scottsdale, Arizona), 36 to 42% removal of DOC was observed during the BDOC test. The amount of BDOC in the wastewater depended not on the concentration of DOC, but on the effectiveness of pretreatment. Abiotic adsorption capacity of wastewater effluent varied from 6 to 18%. Molecular weight distribution analyses showed that more than 50% of DOC in the Scottsdale concentrate had a molecular weight of less than 1000 Da, and no significant change in distribution profiles occurred after approximately 12% abiotic adsorption with both soils with acclimated microorganisms (SAT soil) and soils without acclimated microorganisms (non-SAT soils). Hence, preferential adsorption was not observed and the presence of acclimated microbes did not influence adsorption.     

一体化A/O工艺碳氮比对脱氮除碳的影响

依据好氧硝化和缺氧反硝化生物脱氮除碳工艺原理，设计了一体化生物膜法A/O反应器，并将其应用于生活污水处理，取得了理想的处理效果。实验结果表明，水力停留时间HRT＝12 h，COD进水浓度处于150～500 mg/L范围内，COD的去除率均在90%以上，且出水均在40 mg/L以下；当C/N比为8.5以下时，NH₃-N去除率高于90%，其出水浓度小于5 mg/L；当C/N比为7.5左右时，具有较高的总氮脱除效果，TN去除率可达到70%。     

Transformation of molecular weight distributions of dissolved organic carbon and UV-absorbing compounds at full-scale wastewater-treatment plants.

The molecular-weight distribution (MWD) of wastewater dissolved-organic carbon (DOC) was determined in samples from seven full-scale wastewater-treatment plants (WWTPs) that use different biological treatments (air activated sludge [air-AS], pure-oxygen AS [O2-AS], and trickling filters). The research objective was to determine how different biological treatments influenced the MWD of wastewater DOC. Primary sedimentation effluent DOC from most of the WWTPs exhibited a skewed distribution toward the low-molecular-weight fraction (MWF) (40 to 50%, < 0.5 K Daltons [KDa]). The Air-AS effluent DOC exhibited a centrally clustered distribution, with the majority of DOC in the intermediate MWF (0.5 to 3 KDa). The O2-AS effluent DOC exhibited a skewed distribution toward the high MWF (> 3 KDa). The removal of DOC by air- and O2-AS bacteria followed trends predicted by a macromolecule degradation model. Trickling-filter effluent DOC exhibited a skewed distribution toward the high MWF (50% DOC, > 3 KDa).